The Flow Cytometry and Cell Sorting Core is an established core for the VDDRC. It has been supported on member requests and approved by the Executive Committee and the Scientific Advisory Board with substantial institutional support provided by the university. This core provides access to state-of-the-art equipment for analytical cytometric analysis, ceil counts and viability, and cell sorting, and it provides expert training and consulting on the use of these methodologies. The core facility maintains three LSRII analytical cytometers, a new Fortessa analytical machine, two FACSAria cell sorters, a Guava sheathless cytometer and associated data processing and software workstations. We offer paramagnetic pre-sorting with a Miltenyi AutoMACS. The core provides both Mac and PC workstations, an extensive toolbox of software for flow cytometry, and digital backup of data on a remote server. The core also houses facilities for immunologic assays using automated ELISpot readers, as well as access to a plate-loading cytometer for cytokine bead arrays or multiplex assays for other soluble factors. The staff provides both group and one-on one instruction to facilitate development of acquisition and analysis skills for all users. Trained users can use the analytical cytometers directly; sorting is an assisted-only service. The core also has worked with several of the VDDRC investigators to develop novel sorting techniques for elements of subcellular compartments such as vesicles. This technically forward work requires custom modification of the sorting cytometer in collaboration with the manufacturer, and involves a large number of technical components from gradient preparations, staining, lasers and fluidics, and downstream collection and proteomics analysis. This innovative work using polarized epithelial cells could not be conducted by individual investigators apart from the development team we have created. The core maintains an active development program to keep the instrumentation and systems current, functional, accessible, and easy to use. In fact, a number of our machines have been extensively customized with four or five lasers and special PMTs to accommodate user protocols. Individual researchers could not support this type of high-quality cytometry in their own labs due to the high cost of the instrumentation and maintenance. This core improves human health through the provision of technologies that increase prevention, diagnosis or treatment of digestive disease disorders.